Fluid pump for medical purposes and measuring chamber therefor

ABSTRACT

Fluid pump for medicinal, especially endoscopic, applications having a transport channel led through a drive, a device possessing a measuring chamber for measuring the pressure of the fluid conveyed in the transport channel and control means for the automatic control of the behaviour of the pump, in particular its transport behaviour, as a function of the measured pressure and as a function of a code value contained in code value carrier means which are provided on or in the measuring chamber, wherein the code value is detected during and/or after fixing of the measuring chamber on the pump housing by read-out means in the fluid pump.

[0001] The invention relates to a fluid pump according to theintroductory part of claim 1 and a measuring chamber according to claim7.

[0002] Patent specification DE 195 25 926 C1 discloses a peristalticpump system in which a measuring device is inserted into the pump systemhose line after the pump. This measuring device downstream of the pumpdetermines the fluid transport volume of the pump by pressuremeasurement. In this case the measuring device is built up in simplemanner as a block so that it can be removed from a mounting in orderthat the test housing can be disinfected without complication. At thesame time the fluid pressure is transmitted from the interior of thetest housing to the outside via openings which are covered tightly by amembrane.

[0003] In so doing the test housings can be built up of reusablemeasuring chambers to be disinfected or alternatively of single-useproducts packed in sterile manner. Due, however, to the removability ofthe measuring chamber or the design of the measuring chamber as aseparate, exchangeable accessory part the critical and seriousdisadvantage, especially in the field of medicine, arises that ameasuring chamber which is actually destined and suitable for a certainfirst pump system is inadvertently employed in a different pump systemas a result of which the proper functioning of the latter pump system isput in question.

[0004] This is especially the case, for example, when pump systems withtheir respective measuring chambers are on hand from differentmanufacturers as accessories and the measuring chambers from a firstmanufacturer can be inserted into the pump systems of a differentmanufacturer (in particular in this case when the external dimensions ofthe measuring chambers from the different manufacturers are identical toone another) but properties of the measuring chambers of importance forthe pressure measurement differ from manufacturer to manufacturer. Thiscan cause faulty operation of the pump systems.

[0005] Accordingly, it is the object of the present invention to specifya fluid pump having a pressure measuring chamber and a pressuremeasuring chamber therefor which is particularly simple and robust tohandle in clinical practice, for which the measuring chambers areparticularly inexpensive to manufacture in industrial mass productionand wherein the inadvertent use of a measuring chamber in a pumpunsuitable for this measuring chamber is prevented.

[0006] These tasks are solved according to the invention by a fluid pumpaccording to claim 1 and a measuring chamber according to claim 16.

[0007] The invention according to claim 1 exhibits the followingadvantageous characteristics.

[0008] Due to the fact that code value carrier means are provided on themeasuring chamber of the fluid pump according to the invention theparticular advantage is achieved that code values can be entered intothese code value carrier means and hence the measuring chamber can beindividualised. Such code values can be alphanumeric values or othervalues which carry information about type and/or performancecharacteristics of the measuring chamber or its manufacturer. Due to thefact that during and/or after fixing on the pump housing of the fluidpump—for example by insertion into a holding device in the fluidpump—the code value carrier means can be recorded by the read-out meansof the fluid pump a particularly unpractical additional work step in thepractical clinical field is avoided from the outset, for exampleestablishing an electric cable connection between the code value carriermeans and the fluid pump or for instance the manual read-out of ascanning code applied to the housing of the measuring chamber by amanual scanner connected to the fluid pump.

[0009] Due to the fact that read-out means are provided which can readout the code value from the code value carrier means the fluid pump canmatch its operational behaviour in operation to the measuring chamberemployed according to the code value entered into the code value carriermeans on the measuring chamber. This matching can consist, for example,in a change in the transport behaviour of the pump or the pump denyingits operation for transport.

[0010] The ability to fix the pressure measuring chamber on the pumphousing can be achieved for instance in that the housing of themeasuring chamber and the fluid pump are equipped in such a way that themeasuring chamber is insertable into a holding device on the fluid pump.Thus, it is particularly easy to fit it into a tube line withoutadditional fastening effort and to remove it again without appreciablyincreasing the length of the tube line in doing so. Such a housingdesign can be achieved for instance in that the box-shaped housing has asmooth and robust surface which is scratch-proof and resistant tofracture and in which fragile outer parts are dispensed with.

[0011] Advantageous refinements of the invention according to claim 1are possible according to the subsidiary claims referring back to thelatter and are explained below.

[0012] The adaptation of the pump behaviour is brought about by thefunctions of the control means of the fluid pump which control thebehaviour of the fluid pump as a function of the code value recorded bythe read-out means and held in the code value carrier means of themeasuring chamber. In this way it is made possible when using differentmeasuring chambers having at least externally identical geometricdimensions to control the operating behaviour of the pump by usingdifferent code values: for instance in that a first measuring chamberhaving a first code value triggers the transport properties of the pumpfor interventions in the field of the central nervous system andalternatively a second measuring chamber having a second code value inthe same fluid pump triggers the transport properties for endoscopicinterventions in the knee.

[0013] In this way it can also be effectively prevented that erroneoususe of a measuring chamber not belonging to the pump results, forexample, in the pressure of the transported fluid and hence itstransport flow rate being wrongly determined or a measuring chamberbeing used in association with the fluid pump which does not meet theproperties demanded and specified by the pump manufacturer.

[0014] A particularly simple implementation of the interplay of the codevalue carrier means and read-out means is to implement the code valuecarrier means as one or more, for example pin-shaped, profiles on themeasuring chamber housing which due to a suitably complementary profilein the pump housing allow complete fixing of the measuring chamber onthe pump housing only when the pattern (corresponding to the code value)formed by the pins matches that specified by the profiling of the pumphousing. The fluid pump can then be implemented in such a way that itassumes its transport operation only when a measuring chamber iscompletely fixed on it.

[0015] Other methods of implementing the control means, especially whenthey are realised by functions suitable for the purpose of electroniccontrol means, are based on the principle that from the code valuecarrier means a code value contained therein is detected by the read-outmeans and checked by means of a suitable control logic circuit to seewhether this code value (or this number of code values) agrees with thecode value(s) expected by the control logic circuit of the fluid pumpand/or held therein and thereupon by simple insertion of a measuringchamber coded in suitable manner the transport behaviour of the fluidpump is adapted according to the desired medicinal use or blockage ofthe pump is triggered so that safe operation of the pump can be ensured.

[0016] A particularly advantageous method of implementation is when thecode value carrier means contain means for optical and/or electricand/or magnetic and/or mechanical code value storage and also means fortransmitting a code value in one of the aforesaid ways insofar as thesecannot be read out directly from the code value carrier means by theread-out means of the fluid pump.

[0017] In doing so the read-out means need not necessarily embody thesame principle of implementation as the code value carrier means but beadapted to these. Thus, it is conceivable for instance to havemechanical code value storage by means of prominences on the housingwhich are detected optically or alternatively mechanical scanning of amagnetic storage system.

[0018] It is particularly advantageous for the code value contained inthe code value carrier means—a plurality of code values simultaneouslyis equally conceivable—represent information relating to the technicalproperties of the measuring chamber (such as flow cross-section of thetransported fluid or cross-section of the measuring nozzle) and/orrelating to the manufacturer (measuring chamber manufacturer or fluidpump manufacturer) and/or relating to the intended mode of operation ofthe pump (desired transport volume, permitted transport tolerance indifferent medicinal applications).

[0019] A practical and particularly low-cost variant for implementingthe coding means is, for instance, to provide on the housing of themeasuring chamber mechanically scanable prominences and/or depressionsand/or excavations. By this means a low-cost and robust solution for thecode value carrier means is selected whose serviceability is notimpaired by moisture and/or chemicals, radiation and heat. If these codevalue carrier means are arranged on one side of the measuring chamberhousing so that they come into direct contact with the read-out means ofthe fluid pump the scanning of the code pins can take place by means ofelectric pressure contacts, as in a pressure-sensitive keyboard forinstance. Particularly advantageous is to arrange the code value carriermeans and read-out means in such a way that they are placed in effectivecontact with one another directly by fixing the measuring chamber on orin the housing of the fluid pump without further action.

[0020] Other methods of implementation are also conceivable, however:the use of a barcode for instance as the code value carrier means and abarcode reader as the read-out means of the fluid pump as well asrepresentation of the code value in the code value carrier means bycolours. In these two forms of coding it is advantageous that thebarcode or the colours as an implementation of the code value carriermeans afford a very low-cost method of implementation on the part of themeasuring chamber which is important because the measuring chambers incomparison with the fluid pumps are produced in very large numbers.

[0021] A somewhat more costly method of implementation provides for anintegrated circuit as the code value carrier means in which circuit atleast one code value is stored. In doing this it is advantageous thatthe number of code values or the information contained in the code valuecan be much more extensive. In connection with this a particularlyadvantageous method of implementation is to transmit the code value fromthe code value carrier means to the read-out means by electromagneticsignals.

[0022] Particularly with regard to the practical clinical use of themeasuring chambers it is particularly advantageous to provide thehousing of the measuring chamber with means for the uniqueidentification of the orientation of the housing relative to the fluidpump housing. When fixing the measuring chamber on or in the pump, eg ina holding device provided for this purpose on or in the pump and by atranslational movement of the measuring chamber in the longitudinaldirection of the measuring chamber housing, this is a simple way ofpreventing it being inserted the wrong way round, in particular with thechamber connected counter to the planned direction of flow in the tubingcircuit. By providing such means the user need not take any particularcare when inserting the chamber. For example, they can take the form ofa special shape for the housing in association with a complementaryshape on the fluid pump such as, for instance, the use of asymmetricgeometric properties in housing geometries.

[0023] A further advantageous refinement of the measuring chamberprovides for a membrane on the measuring chamber onto which the pressurefrom the interior of the measuring chamber can be transmitted throughopenings provided for this purpose in the measuring chamber housing,wherein the openings are tightly covered by the membrane so that due tothe leak-proofness of the covering of the openings by the membrane thetransported fluid remains in a closed system in the region of themeasuring chamber.

[0024] In combination with the membrane and in particular with regard topractical use it is advantageous to equip the measuring chamberadditionally with a membrane protector completely covering the membraneby which means the membrane is reliably protected on the measuringchamber in practical use such as transport or disinfection andunintended tearing or bulging of the membrane is prevented. In doingthis it is particularly advantageous for the membrane protector to beopened by lateral displacement along the measuring chamber housing.

[0025] For example, this can be constructed in such a way that on fixingon the fluid pump the membrane protector is automatically caused toexpose the membrane and hence allow the fluid pump contact with themembrane, for fluid sensors in the fluid pump for instance. By thismeans in particular the disadvantage of a sheath-like or hood-like coveris avoided which must be put in position or removed with some effort byhand and which in particular can easily be lost. In a manner analogousto the automatic opening of the membrane protector on fixing themembrane protector can be closed on removal of the measuring chamber outof or from the fluid pump.

[0026] A particularly practicable embodiment for the lateraldisplaceability of the membrane protector constructed as a plate takesthe form of guide rails along the measuring chamber housing which can beimplemented as mouldings on the measuring chamber housing.

[0027] By means of the automatic opening and closing of the membraneprotector on the measuring chamber when it is fixed on or in the fluidpump there is no need for unwieldy manual pushing aside or removal ofthe membrane protector—or putting it back on—which might require theuser to use both hands.

[0028] Another advantageous embodiment of the measuring chamber providesfor locking means on the measuring chamber which hold the housing byfriction fitting and/or form fitting after it is fixed on a fluid pump.The means of engagement as preferably constructed in such a way that onfixing they produce a clearly perceptible click and fixing and removalcan be effected by simple and direct application of translational force,in particular without operation of additional unlocking devices.

[0029] It is, furthermore, advantageous to provide a pump segment whichis fixedly connected by clamping to the measuring chamber on the inletside. This has the advantage that on each change of measuring chamberthis pump segment is also exchanged. This is of particular importancewhen the drive of the fluid pump constructed as a peristaltic pump isimplemented via a roller wheel and for that reason on the pump segmentconstructed as a flexible tube particularly high demands are imposed onthe mechanical properties of the pump segment. These mechanicalproperties are subject, however, to particularly marked ageing orattrition during use so that regular replacement must be ensured. In thepresent embodiment this is ensured by the fixed attachment to themeasuring chamber.

[0030] Another advantageous embodiment provides for a flow channel inthe measuring chamber and the construction therein of a measuring nozzlereducing the flow cross-section of the fluid streaming through the flowchannel, wherein ahead of and following the measuring nozzle openingsare arranged for externalising the measuring chamber which allowmeasurement of the pressure.

[0031] The characteristics of the invention exhibit the followingadvantageous effects.

[0032] Due to the fact that the measuring chamber contains code valuecarrier means in which at least one code value is present and whichcontain means for code value storage and transmission it is achievedthat due to the code value contained it is achieved in simple mannerthat the measuring chamber can be individualised and the compatibilityof measuring chambers with fluid pumps from different manufacturers canbe selectively controlled as described above in more detail in thestatements about the advantageous effects of the fluid pump according toclaim 1. Compatibility and individualisation can be provided in thismanner without the need for producing differences in the housing or inthe mechanically fitted shape which are costly in production terms. Bythis means the effects of scale in large-scale industrial production areexploited since housing production for all measuring chambers can ensuein the same way according to external dimensions and in this wayrationalisation effects in production arise.

[0033] Advantageous refinement of the invention according to claim 7 ispossible according to the subsidiary claims referring back to the latterand correspondingly to the refinements of the fluid pump relating to themeasuring chambers.

[0034] The invention is explained below with reference to an exemplifiedembodiment. The drawings show:

[0035]FIG. 1 a wedge-shaped measuring chamber with a membrane in whichthe membrane protector is in the open and closed state and bearing codevalue carrier means in the form of code pins;

[0036]FIG. 2 a cut-away view of the measuring chamber from the side ofthe housing opposite the membrane, a view at right angles to themembrane side and a view of the membrane side;

[0037]FIG. 3 a fluid pump constructed in the form of a peristaltic pumphaving a roller wheel and roller wheel and holding device foraccommodating the measuring chamber pushed in from the side;

[0038]FIG. 4 the fluid pump illustrated in FIG. 3 with inserted andlocked measuring chamber as illustrated in FIGS. 1 and 2;

[0039]FIG. 5 a detailed version of that shown in FIG. 1 with guide railsand locking means, wherein in this case the housing shape is aparallelepiped; and

[0040]FIG. 6 a detailed version of that shown in FIG. 4 showing guidanceof the pump segment on insertion and on stabilisation of the measuringchamber.

[0041]FIG. 1 shows an exemplified embodiment of a measuring chamberaccording to the invention. The measuring chamber has a block-likehousing 1 with a level surface. On one end face of the block-likehousing 1 a pump segment 5 is clamped in place and inserted into theother end face is a tube connection 6 which each form the extension of aflow channel 7 not illustrated in more detail in this figure. Inaccordance with the invention and as described later in association withFIGS. 3 and 4 the measuring chamber or the housing 1 is pushed into amounting which at present is not necessarily fastened to a pump.

[0042] Likewise on the end face of the housing 1 accommodating the pumpsegment 5 there are located code value carrier means 4 implemented inthe form of code pins. These code pins contain a code value which, forexample, contains the name of the company which produced the measuringchamber and the cross-section of the flow channel in codified form. Thecode pins 4 are located on the side located in the plug-in direction ofthe measuring chamber in the holding device of the fluid pump providedfor this purpose. In this special case, but not generally, the plug-indirection is the side from which the fluid flows into the measuringchamber.

[0043] A membrane 2 can also be seen which covers openings 8 and 8′between the flow channel and the outside of the measuring chamber whichare not illustrated in more detail in this figure (see FIG. 2). Amembrane protector 3 is constructed in this case in the form of a platewhich is displaceable to the side and is guided in stable and securemanner to prevent it slipping out by guide rails 13 projecting from thehousing above and below the membrane protector plate 3. Thus, FIG. 1 Ishows the membrane protector in the open state and FIG. 1 II themeasuring chamber with the membrane protector in the closed state. Whenhandling the measuring chamber when it is not inserted in the holdingdevice of a fluid pump the state depicted in FIG. 1 II is the normalstate. Here a return structure can be provided in the housing 1 whichensures that insofar as a lateral displacement force is not used themembrane protector 3 always returns to the basic state as depicted inII.

[0044]FIG. 2 shows the same measuring chamber in cut-away from the side(I) located opposite the membrane, in cut-away perpendicular to themembrane side (II) and from the membrane side (III).

[0045] In FIG. 2I the pump segment 5 can be seen in the way it isplugged into the inlet of the flow channel designated by 7. The flowoutlet in the form of the tube connector 6 is also clearly visible. Ishows how the membrane surface 2, illustrated by the continuous line ofthe rounded rectangle surrounding the area 2, covers the openings 8 and8′ illustrated as the interior of the dotted rings located therein.Located above this the membrane protector 3 is illustrated by a dottedline. Likewise illustrated by dotted lines are the code pins 4 in oneend face of the housing.

[0046] The view II turned with respect to I by 90° in the horizontalplane shows the membrane protector 3 in the guide rails 13 provided forthis purpose which continue to the side on the right to the outside sothat the membrane protector can be pushed to the right beyond theboundary of the measuring chamber housing. In this view the openings 8and 8′ are also clearly visible which connect the inside of the membrane2 (not illustrated in more detail in this view II) to the flow channel7.

[0047] The view III shows the closed membrane protector 3 as acontinuous line and located behind it in dotted lines the membrane 2 andthe openings 8 and 8′ which lead to the flow channel 7 located inside.It is also shown how the membrane protector is held in the guide rails.Where the continuous line of the membrane protector plate 3 engagesbehind the likewise continuous projection engaging round the plate 3 attop and bottom the continuous line of the membrane protector 3 passesover into a dotted line.

[0048] A measuring nozzle located between the openings 8, 8′ in the flowchannel is not illustrated in more detail but is readily imaginable,especially in the view II between the openings 8 and 8′, as a taperingof the flow channel 7.

[0049]FIG. 3 shows an exemplified embodiment of a fluid pump accordingto the invention constructed in the form of a peristaltic pump which inthe present case is designed to accommodate the measuring chamber asimplemented in the exemplified embodiment in FIGS. 1 and 2 describedabove so that the fluid pump and measuring chamber are activelyconnected according to the invention.

[0050] Other forms of fluid pumps of analogous design with regard to theactive connection to the measuring chamber may contain a drive based onthe peristaltic principle but without a roller wheel for producing theperistaltic effect or, furthermore, a drive based on a rotor or impellerwhich for its part may be driven by magnetism and may also be arrangedin the axial direction relative to the transport channel. A design inthe form of a gear-type pump having a closed gear chamber is alsoconceivable.

[0051] In the present exemplified embodiment in the form of aperistaltic pump the housing 15 has a roller wheel 9 around which aflexible tube can be placed and the holding devices 10. Accordingly, thetransport channel is constructed as a tube line.

[0052] The holding devices 10 are mouldings on the pump housing andformed in such a way that they completely accommodate and in doing sosecurely encompass the block-like housing 1 of the measuring chamberwhich is of prismatic construction with a trapezoidal outline on themembrane side. For this purpose the holding devices 10 have slopingguide surfaces 14 which engage with the sloping side surfaces of thehousing.

[0053] At the end of the holding devices 10 viewed in the insertdirection at least one read-out means constructed as a reading contact11 is arranged which works together with the code pins 4. The at leastsingle reading contact 11 and the code pins 4 may also have differentembodiments, that is to say be implemented in mechanical, eg pins andholes engaging in one another, electrical, optical and/or mechanicalmanner.

[0054] Through mechanical scanning of the corresponding code pin 4 ofthe measuring chamber the reading contact 11 is able to read out thesingle-place code value located therein. In this example it is checkedwhether the measuring chamber to be inserted in the mounting 10 iscompatible with the pump.

[0055] The housing 15 of the pump is provided with pressure sensors 12,12′ which work together with the measuring chamber. For this purpose thepressure sensors 12 and 12′ are arranged in such a way that when themeasuring chamber is inserted they are directly in active contact withthe membrane 2 exposed from its membrane protector 3 as soon as themeasuring chamber is completely pushed in and locked in place, whereinthe pressure sensors are located directly opposite the region of theopenings 8 and 8′ concealed behind the membrane. Locking means, whichare not illustrated, are provided for locking the measuring chamber tothe holding device 10. These are fitted on the holding device 10 and/orthe housing 1 of the measuring chamber.

[0056] The presence of only one read-out means 11, ie a mechanicalscanner for only one code pin, serves only to improve the clarity ofpresentation. A plurality of read-out means can of course be presentwhich can advantageously be arranged (as in the intake of a stripscanner) one above the other in a row as suggested in the illustrationof the code pins 4 in FIG. 1 I.

[0057]FIG. 4 shows the fluid pump illustrated in FIG. 3 with themeasuring chamber inserted and locked in position as illustrated in FIG.1 I. At the start of the insertion operation the membrane protector 3 iscaught by a catch, which is not illustrated in more detail, at the levelof the pressure sensors 12, 12′ and held so that the membrane 2 on themeasuring chamber is exposed as the insert movement continues. In thiscondition of being fully inserted and locked in place the reading means11 make contact with the code value carrier means 4 so that the controlmeans in the system, which may also contain the means for determiningthe transport volume from the signals of the pressure sensors, determinewhether the system is ready for operation and/or in which way the systemoperates. At the same time the pressure sensors are in active contactvia the membrane 2 with the openings 8 and 8′.

[0058] If the measuring chamber is equipped with a suitable returndevice then on unlocking and removing the measuring chamber from theholding device on the fluid pump the membrane protector 3 advances againover the membrane to protect it without any action by the user. Fromhere the measuring chamber can be collected without any special care andbe disinfected which proves to be advantageous especially in practicalclinical operations.

[0059]FIG. 5 shows a more detailed version of that shown in FIG. 1 withguide rails 13 which grip around the sides of the membrane protectorplate 3 covering the membrane 2 and in which recesses are provided atthe right-hand end in the drawing into which the correspondingly shapedright-hand ends of the membrane protector plate 3 engage in frictionfitting manner and in this way secure the position of the membraneprotector.

[0060] Also illustrated again are the code value carrier means 4constructed as code pins which here take the form of convex, pin-likemouldings on the housing together additionally with the engaging means20 each located on the top or bottom of the measuring chamber housingwhich on fixing the measuring chamber on or in the housing of the fluidpump engage with a clearly perceptible click and secure the measuringchamber in friction fitting manner against inadvertent detachment fromthe fluid pump. Furthermore, in this figure the measuring chamberhousing has an elastic attachment 21 which positions the measuringchamber securely inside the mounting after fixing implemented asinsertion in a holding device of the fluid pump in that the elasticattachments 21 from one side push the measuring chamber located in themounting away from one side and against the other side where the sensorsare so that no unintended movement of the measuring chamber housingrelative to the fluid pump can take place.

[0061]FIG. 6 shows how fixing of the measuring chamber on a fluid pumpimplemented in the form of a peristaltic pump can be carried out.

[0062] Brought into the position shown the pump segment 5, which in thisfigure is shown merely as a short length and in reality is many timeslonger, can be gripped by one hand and at the same time the measuringchamber housing connected to the pump segment 5 is moved into theholding device 10 by pulling in the direction of the roller wheel 9. Inthe course of this movement the person operating the instrument canguide the pump segment clockwise round the roller wheel into the holdingdevice 15 and finally clamp it in the locking device 16. In this way thepump segment is fixed in a stable position and the measuring chamber isfitted securely into the holding device. The elastic attachments 21 hereensure that the measuring chamber is pressed against the pressuresensors 12 for the measuring chamber and prevent unintended slippagewhile the locking means 20 produce a clearly perceptible click onengagement as soon as the measuring chamber reaches the fixed positionof operational readiness on the fluid pump and further secure themeasuring chamber against unintended slippage out of the holding device11.

[0063] Another characteristic of the measuring chamber illustrated inthis figure is that it has a label surface 30 for holding informationsuch as a label bearing the logo of the manufacturer or otherinformation, eg the field of use of the pump, “Only for uteroscopy” forinstance.

1. Fluid pump (P) for medicinal, especially endoscopic, applicationshaving a housing, a transport channel conveyed via drive, a devicepossessing a measuring chamber (M) for measuring the pressure of thefluid conveyed in the transport channel and control means for theautomatic control of the transport properties as a function of themeasured pressure, wherein the measuring chamber is fixable on or in thepump housing, characterised in that the measuring chamber (M) isequipped with code value carrier means (4) containing a code value andthat on or in the pump housing read-out means (11) are provided forregistering the code value during and/or after fixing of the measuringchamber on or in the pump housing.
 2. Fluid pump according to claim 1,characterised in that the control means contain functions forcontrolling the behaviour of the pump as a function of the code valueread out.
 3. Fluid pump according to claim 2, characterised in that thebehaviour of the pump controlled as a function of the code valuecomprises the control of the transport properties of the pump as afunction of the measured pressure.
 4. Fluid pump according to any ofclaims 1 to 3, characterised in that the transport function of the pumpis blockable as a function of the code value read out.
 5. Fluid pumpaccording to any of claims 1 to 4, characterised in that the code valuecarrier means are constructed in the form of optical and/or electricand/or magnetic and/or mechanical means and the read-out means areadapted to the latter.
 6. Fluid pump according to any of claims 1 to 5,characterised in that the code value contained in the code value carriermeans represents information relating to the technical properties of themeasuring chamber and/or relating to the manufacturer and/or relating tothe intended mode of operation of the pump.
 7. Fluid pump according toany of claims 1 to 6, characterised in that the read-out means containelectric pressure contacts.
 8. Fluid pump according to any of claims 1to 7, characterised in that the code value carrier means (4) containprominences and/or depressions on the surface of the measuring chamberrepresenting the at least single code value.
 9. Fluid pump according toany of claims 1 to 8, characterised in that the measuring chamber has ahousing (1) having means for the unambiguous identification of thespatial orientation of the measuring chamber relative to the pumphousing.
 10. Fluid pump according to any of claims 1 to 9, characterisedin that the measuring chamber possesses a flow channel which is providedwith at least one opening to the outside sealed by a membrane and thatopposite the opening at least one pressure sensor actively connected tothe membrane is arranged in the pump housing.
 11. Fluid pump accordingto claim 10, characterised in that the measuring chamber has adisplaceable membrane protector which covers the membrane.
 12. Fluidpump according to claim 11, characterised in that the membrane protector(3) comprises a plate (3) covering the membrane at least in the regionof the openings and running in guide rails.
 13. Fluid pump according toany of claims 1 to 12, characterised in that the measuring chamber andthe pump housing possess locking means which hold the measuring chamberby friction fitting and/or form fitting after it is fixed on the pumphousing.
 14. Fluid pump according to any of claims 1 to 13,characterised in that the measuring chamber has a flow channel (7) and apump segment (5) is provided which is clamped into the flow channel (7)on the inlet side.
 15. Fluid pump according to any of claims 1 to 14,characterised in that the measuring chamber has a flow channel (7) andtherein a measuring nozzle reducing the flow cross-section of the fluidflowing through the flow channel (7) is provided, wherein an opening (8,8′) is arranged ahead (8) of and an opening after (8′) the measuringnozzle in the flow channel.
 16. Measuring chamber (M) suitable for afluid pump (P) according to any of the preceding claims having a housingenclosing a flow channel (7), characterised in that it is equipped withcode value carrier means (4) in which a code value is contained. 17.Measuring chamber according to claim 16, characterised in that the codevalue carrier means are constructed in the form of optical and/orelectric and/or magnetic and/or mechanical means.
 18. Measuring chamberaccording to any of claims 16 or 17, characterised in that the codevalue carrier means (4) contain the at least single code valuerepresenting prominences and/or depressions on the surface of thehousing.
 19. Measuring chamber according to any of claims 16 to 18,characterised in that the code value contained in the code value carriermeans represents information relating to the technical properties of themeasuring chamber and/or the geometric dimensions of the interior andthe exterior of the measuring chamber and/or relating to themanufacturer and/or relating to the intended medicinal field ofapplication.